CamelBak's RaceBak is a revolution in lightweight wearable hydration. This wicking baselayer hides an innovative 72-ounce reservoir that comfortably slips under your jersey for superior aerodynamics and ease of use. It's sleeveless for excellent mobility, has a quarter-length zipper and uses flat-lock stitching throughout for forget-about-it comfort. Your water stays cool thanks to the insulated back panel and tube cover, and the Air Mesh insert ensures your back stays airy and dry. Athletes rejoice - the next generation of hydration is here.